For power converters that provide an output current at their output, power factor correction (PFC) is normally used. The current generated at the output of the converter has a DC component and an AC component. The effective value of the output current should correspond within prescribed tolerances to a setpoint programmed in the converter. It should be noted here, however, that the effective value of the output current emitted at the output depends on the input voltage of the converter. This is why the accuracy of the output current has to be specified in greater tolerances or the overall converter circuit has to be specified for only low input voltage ranges.
To enable the given setpoint output current to be emitted at the output, a control strategy is used that regulates to the maximum value of the output current. However, particularly for a single-stage flyback converter topology, the amplitude of the AC component of the output current is strongly dependent on the input AC voltage.
Stabilizing the output current of the converter makes particular sense if the converter supplies power to one or more lamps, for example, one or more LEDs. Fluctuations in the power supply of the LEDs cause variations in brightness which could have an irritating effect for the observer.
It is the object of the invention to provide stabilization of the effective value of the output current of a converter.